LONDON (AP) ' London police arrested Rebekah Brooks, Rupert Murdoch's former British CEO, in the phone hacking and police bribery scandal Sunday, and the former News of the World editor said she was "assisting the police with their inquiries."

Brooks, 43, was arrested at a London police station at noon Sunday. She is being questioned on suspicion of conspiring to intercept communications ' phone hacking ' and on suspicion of corruption, which relates to bribing police for information.

A statement released on Brooks' behalf said she "voluntarily attended a London police station to assist with their ongoing investigation."

"This was a prearranged appointment," said her spokesman, David Wilson ' although he said Brooks was not aware she was going to be arrested.

The arrest comes just two days before Brooks, Rupert Murdoch and his son James are due to answer questions from a parliamentary committee investigating the hacking. Sunday's arrest throws that appearance before Parliament's Culture, Media and Sport committee into question; Brooks would not have to answer questions that could prejudice a criminal investigation.

Brooks, one of Murdoch's most loyal lieutenants, stepped down Friday as head of his British newspapers. She was editor of the now-defunct News of the World between 2000 and 2003, when some of the phone hacking took place, but has always said she did not know hacking was going on, a claim greeted with skepticism by many who worked there.

At an appearance before lawmakers in 2003, she admitted that News International had paid police for information. That admission of possible illegal activity went largely unchallenged and, at the time, little noticed.

Police have already arrested nine other people connected to Murdoch's British media empire over allegations that the News of the World hacked into the phone voice mails of hundreds of celebrities, politicians, rival journalists and even murder victims. No one has yet been charged.

The arrest also piles more pressure on Prime Minister David Cameron, a friend and neighbor of Brooks, who has met with her many times and invited her to stay at his official country retreat.

Cameron is already under fire for hiring Andy Coulson, who resigned as News of the World editor after two employees were jailed for corruption in 2007, as his communications chief. Coulson resigned from Downing Street in January after police reopened their hacking investigation. He was arrested last week and questioned before being released on bail.

Brooks' arrest is another blow for Murdoch, who is struggling to tame a scandal that has already destroyed one major British tabloid, cost the jobs of two of his senior executives and sunk his dream of taking full control of a lucrative satellite broadcaster, British Sky Broadcasting.

On Sunday, Murdoch took out a second newspaper ad promising that News Corp. will make amends for the phone hacking scandal.

The ad in several U.K. Sunday newspapers, titled "Putting right what's gone wrong," said News Corp. would assist the British police investigations into phone hacking and police bribery. It vowed there would be "be no place to hide" for wrongdoers.

"It may take some time for us to rebuild trust and confidence, but we are determined to live up to the expectations of our readers, colleagues and partners," the ad said.

Last week Murdoch shut down the 168-year-old News of the World after it was accused of eavesdropping on cell phones for years. Sunday was the first day in Britain that the popular, gossipy, muckraking weekly was not on the newsstands.

Murdoch also abandoned his BSkyB takeover bid, and two of his senior executives resigned ' Brooks and Wall Street Journal publisher Les Hinton.

But Murdoch's critics say that is not enough. Labour Party leader Ed Miliband said Sunday that Murdoch has "too much power" in Britain and his share of British media ownership should be reduced. With the News of the World gone, Murdoch now owns three national British newspapers ' The Sun, The Times and The Sunday Times ' and a 39-percent share of BSkyB.

"I think that we've got to look at the situation whereby one person can own more than 20 percent of the newspaper market, the Sky platform and Sky News," Miliband told The Observer newspaper.

"I think it's unhealthy because that amount of power in one person's hands has clearly led to abuses of power within his organization. If you want to minimize the abuses of power then that kind of concentration of power is frankly quite dangerous," he said.

Deputy prime Minister Nick Clegg agreed there should be greater plurality in the media.

"A healthy press is a diverse one, where you've got lots of different organizations competing, and that's exactly what we need," Clegg told the BBC.

Clegg's Liberal Democrat party has asked Britain's broadcast regulator to consider whether News Corp. is a "fit and proper" owner of BSkyB.

Cameron's Conservative-led government and the London police also are facing increasing questions about their close relationship with Murdoch's media empire.

Cameron has held 26 meetings with Murdoch executives since he was elected in May 2010 and invited several to his country retreat. Senior police officers also had close ties to Murdoch executives, even hiring as a consultant a former News of the World editor who has since been arrested for alleged hacking.

Home Secretary Theresa May plans to make a statement in the House of Commons on Monday outlining her "concerns" about close police ties with News International.

Police are under pressure to explain why their original hacking investigation several years ago failed to find enough evidence to prosecute anyone other than News of the World royal reporter Clive Goodman and private investigator Glenn Mulcaire. Detectives reopened the investigation earlier this year and now say they have the names of 3,700 potential victims.

Records show that senior officers ' including Paul Stephenson, the current chief of London's Metropolitan Police ' have had numerous meals and meetings with News International executives in the past few years. The force also hired Neil Wallis, a former News of the World executive editor arrested last week in the phone hacking, as a part-time PR consultant for a year until September 2010.

Stephenson also stayed for free earlier this year at a health resort that employed Wallis to do its public relations. The police force said the stay had been arranged through the facility's managing director, a family friend, as Stephenson recovered from surgery. It said the police chief had not known that Wallis worked there.

Murdoch is eager to stop the crisis from further spreading to the United States, where many of his most lucrative assets ' including the Fox TV network, 20th Century Fox film studio, The Wall Street Journal and the New York Post ' are based.

The FBI has already opened an inquiry into whether 9/11 victims or their families were also hacking targets of News Corp. journalists.